The Alkalinity and Calcium Hardness TesTabs test kit uses one tablet per test factor which is added to a test tube of water sample to develop a color. Sample water is added performing a back titration until an endpoint color change occurs. The results are read directly from the test tube which measures Alkalinity and Calcium Hardness from 60 to 400 ppm. The kit includes simple to read instructions, 30 TesTabs tablets, a water sample bottle along with a preprinted test tube with Alkalinity and Calcium Hardness levels.